Chinese police have detained a suspect for allegedly poisoning the frozen dumplings which were later exported to Japan and sickened 10 people two years ago, said the Ministry of Public Security Friday.

The suspect, Lu Yueting, 36, put poisonous substance in the frozen dumplings when he worked as a temporary employee in Tianyang Food Plant based in north China's Hebei Province, the ministry said in a statement.

Lu was dissatisfied with his payment and did not go on well with several colleagues, so he decided to revenge, the statement said.

He has confessed and the police also have found injectors he used to poison the dumplings and collected several witness accounts, the statement said.

Japanese media reported in January 2008 that 10 people fell ill after eating frozen meat dumplings produced by Tianyang.

Shortly after the incident, the plant was investigated by both Chinese and Japanese authorities, but no problems were found in production.

Before the incident, the plant had been exporting to Japan for 10 years.

The case is still in the process of handling, the ministry statement said.